Sound system



Nov. 12, 1929, THOMPSON 1,735,095

SOUND SYSTEM Filed March 15, 1922 26 Harry JfaroZaZ fizbmpsorz,

4mm, 4% @231 fff Patented Nov. 12, 1929 UNITED STATES PATENT OFFICE HARRY HAROLD-THOMPSON, OF KANSAS CITY, MISSOURI, ASBIGNOB '10 RADIO (JOR-v POBLTION OF AMERICA, 01 NEW YORK, N. 'Y., A CORPORATION 01 DELAWARE SOUND SYSTEM Application filed March 15, 1922. Serial No. 548,888.

My invention relates to a new and useful combination of coacting elements for transmitting, receiving and translating radio waves, and the invention consists generally of a phonograph, or a phonograph cabinet,

a radio apparatus associated with said phonograph, or cabinet, and a device in circuit with said radio apparatus and which may be applied to a telephone or a phonograph to trans '10 mit or receive and ampli the vibrations of the radio apparatus or t e vibrations pro-- duced by a record placed in operative relation to the needle of the phonograph.

An important feature of the invention re- 1 sides in a device which may be employed either as a transmitter, a receiver, a reproducer, or a recorder, and which is of novel construction and arrangement, as will hereinafter ap ear.

In or er that the invention may be fully understood, reference will now be had to the accompanying drawing, in which Fig. 1 1s a perspective view of a cabinet containing a radio apparatus and a phono- 25 graph which latter is equipped with one of the above-mentioned devices.

Fig. 2 is an enlarged vertical section of the transmitter, receiver, reproducer, or recorder equipped with an ear-piece.

F1g. 3 is a diagram of a radio transmitting and receiving apparatus equipped wlth my devices. 4

Fig. 4 is .a detail of a phonograph tone arm equipped with a holder for supporting a telephone or radio receiver, ear piece, or transmitter.

Fig. 5 is a cross section of said holder supporting a receiver. I

In carrying out the invention, I employ a phonograph cabinet 1 equipped with a phonoraph 2 and a drawer 4 containing a radio recelving apparatus 6.

8 designates my device which consists of a diaphragm 10, a needle arm 12, electro. magnets 14, and a casing 16 which encloses all of the foregoing elements, excepting the outer end of the needle arm 12.

The diaphragm is held in position b a pair of oppositely-disposed rubber or 0t er .50 insulating rings 18, which are interposed between the two detachable members 20 and 22 of the casing 16. The needle arm 12 is fulcrumed at 24 and provided at its outer end With a socket 26 and a set screw 28 to hold the usual needle within said socket 26 when the device 8 is used for reproducing and translating vibrations of a record in position on the phonograph 2. The inner end of the needle arm 12 is secured to the diaphragm 10 and provided with an armature 30 responsive to the electroma nets 14 having wires 32 leading to a pair 0? terminals 34 ada ted to be engaged by a corresponding pair 0 terminals 36 carried by a plug 38 adapted to enter a corresponding socket in the casing 16, as disclosed by Fig. 2. The armature 30is'removably and adjustably connected to the needle arm 12, by a set screw 31 so that said armature 30 may be a plied to the needle arm of any phonograp in which instance the member 20 0f the casing 16 may be suitably connected to the phonograph for the purpose of positioning t e electromagnets 14 1n proper relation to the armature 30. The electromagnets 14 are mounted on a plate 15, adapted to be adjusted by a set screw 17 to carry said electromagnets 14 toward or away from the armature 30, to obtain the best results. The casing 16 is enlarged near its central ortion and its back member 22 is equippe with a nipple 40 over which an ear piece 42 may be slipped, as shown by Fig. 2, or whereby said casing 16 may be readil applied to the tone arm 44 of the phonograp 2, as disclosed by Fig. 1. While I have shown an ear-piece 42 applied to the nipple 40 it is to be understood that a horn or any other sound amplifier may be applied to such nipple. In the diagram Fig. 3, which shows the circuits of an ordinary radio apparatus equipped with my devices 8 and '8; 29 designates the transmitter set in which 31 designates the dynamo; 33 the choke coils; 35 a condenser; 37 an are; 39 an inductance coil; 41 the antenna; 43 a hot-wire ammeter;

45 a switch; 8 the transmitter; 47, 49 and 51 circuit wires; the antenna of the receiving station; 52 the lead extending from the antenna 50 to the ground; 54 the trans former; 56 and 58 condensers; 60 the audion;

and 72 batteries; 8 the reproducer; and 74, 76 and 7 8 circuit wires.

The generator 31 supplies the current through the wires Q7 and 49 which burns the are 37. The inductance coil 39.is shunted around the-arc 37 through the wire 51, with the condenser 35 in series. The upper terminal or the secondary of the inductance coil 39 leads to the aerial 4:1, and the lower terminal to the hot-wire ammeter 43, the switch as and the transmitter 8. The choke coils 33 prevent the alternations set up by the are 37 from flowing back onto the line 47. The alternations charge the condenser 35 which discharges through the turns oi the inductance coil 39. This induces a like current or" high potential in the secondary turns of the coil 39, the current flowing through the aerial wire 41 and to the ground through the hot-wire ammeter 43, through switch 45 and transmitter 8'. It the transmitter 8 be spoken into, the diaphragm 10 will he set in vibration and the antenna 41 will send out waves impressed with modulations of the spoken words. This wave motion is picked up by the aerial 50 of the receiving set and conducted down to the ground through the turns of the transformer 4;. A like current is produced in the turns of the audion 62 which causes the current flowing through the receiver 8 to vary vibrating diaphragm l0 and thereby translating the current into sound corresponding to the input to transmitter 8.

The transmitting and receiving sets may be installed in the drawer t and either one may be plugged in with the device 8 which is mounted on the tone arm When one of the devices 8 is to he used for reproducing speech or music on the phonograph 2, the plug 38 is removed in order to disconnect said device 8 from the radio apparatus.

Fig. 4: shows a holder 86 applied to the tone arm 88 of a phonograph to hold an ordinary telephone receiver, so that speech or music or other sound received over the telephone may be amplified by a phonograph casing; a plate carried by the set screw; and,

electromagnets carried by the plate; said magnets being disposed on said plate so as to mes es actuate said armature when said needle is out of contact with the phonograph record.

In testimony whereof I afiix my signature.

HAROLD THOMPSGN. 

